Environmental Engineering Reference
In-Depth Information
Costs associated with hybridization are significantly increased by the addition
of electric drive subsystems and their supporting components. To illustrate this
case we assume a 42 V PowerNet enabled, ISG system installed in a mild hybrid.
Table 4.27 is presented here as a cost walk of the ISG system and its supporting
subsystems for three specific cases of vehicle power supply: (1) 42 V PowerNet,
(2) 150 V hybrid and (3) 300 V or higher voltage hybrid. In all three cases the costs
associated with installation of the vehicle power supply are included in the form of
battery, wiring harness and thermal management.
Table 4.27 presents some interesting insights into the economics of hybridizing
a conventional vehicle. At the relatively low power level of 10 kW, the installation
costs are nearly equally split between the costs associated with adding the ISG
hardware (battery, inverter and machine), and the necessary supporting subsystems
for steering, braking and cabin climate control, along with thermal and power
management. Increasing the system voltage shifts the relative proportions, but does
not change the cost breakdown; it is still virtually an even split between the hybrid
technology and subsystems needed to support it.
It should also be apparent that had hybridization taken place after x-by-wire
functionality was already in production, the installation costs of hybridizing such a
vehicle would be cut in half. This is because all the major supporting subsystems
would already be in place for steering, braking (including vehicle stability), cabin
climate control and thermal management.
Table 4.27 Mild hybrid vehicle cost walk (
P
= 10 kW)
Cost walk
42 V
(%)
150 V
(%)
300 V
(%)
Comments
ISG system
Battery
9
11
14
VRLA
Inverter
21
19
18
MOS - 42 V and 150 V,
IGBT at 300 V
Electric machine
11
12
11
Asynchronous
Wiring and conn.
2
4
5
Special insulation required
above 60 V
Subtotal
43
46
48
Supporting systems
Electric water pump +
electric fans
2
2
2
Thermal management
components
dc/dc converter
9
10
11
Required in dual-voltage
systems
Electric assist steering
13
12
11
Motor on steering rack
Electrohydraulic brakes
16
15
14
EHB hardware with ABS cost
offset
Electric assist air
conditioner
17
15
14
2 kW electric drive components
added
Subtotal
57
54
52
Total
100
100
100
